Non-aqueous electrolyte lithium secondary battery

Abstract

A non-aqueous electrolyte secondary battery having a low manufacturing cost and a high energy density and being excellent in the high rate charge/discharge characteristic and in the characteristics in operation at high temperature provided by an improvement on its positive electrode active material is disclosed. The positive electrode active material comprises a specific compound wherein a part of nickel or lithium in LiNiO2 is substituted with another element in a specified range. The element for the substitution comprises Mg, Ca, Sr, Ba, Al Cr, B and Co which may be employed solely or in combination.

What is claimed is: 
     
       1. A non-aqueous electrolyte lithium secondary battery comprising a positive electrode, a negative electrode capable of absorbing and desorbing lithium in a reversible manner and a non-aqueous electrolyte, wherein said positive electrode comprises a compound represented by the formula Li x  Ni 1-y  M y  O 2+z , where M represents at least one element selected from the group consisting of Mg, Ca, Sr and Ba, and 0.05≦x≦1.1, 0.01≦y≦0.3, and -0.3≦z≦0.1. 
     
     
       2. A non-aqueous electrolyte lithium secondary battery comprising a positive electrode, a negative electrode capable of absorbing and desorbing lithium in a reversible manner and a non-aqueous electrolyte, wherein said positive electrode comprises a compound represented by the formula Li x  Ni 1-y  M y  O 2+z , where M is Al, and 0.05≦x≦1.1, 0.003≦y<0.1, and -0.3≦z≦0.1. 
     
     
       3. A non-aqueous electrolyte lithium secondary battery comprising a positive electrode, a negative electrode capable of absorbing and desorbing lithium in a reversible manner and a non-aqueous electrolyte, wherein said positive electrode comprises a compound represented by the formula Li x  Ni 1-y  (Al a  B b  Co c  Mg d ) y  O 2+z , where 0.05≦x≦1.1, 0.01≦y≦0.3, -0.3≦z≦0.1, and (a+b+c+d)≦1, and any three or more of a, b, c and d are never 0 at the same time. 
     
     
       4. A non-aqueous electrolyte lithium secondary battery comprising a positive electrode, a negative electrode capable of absorbing and desorbing lithium in a reversible manner and a non-aqueous electrolyte, wherein said positive electrode comprises a compound represented by the formula Li 1+x-y  Al y  NiO 2+z , where -0.1≦x≦0.1, 0.01≦y≦0.2, and -0.3≦z≦0.2. 
     
     
       5. A non-aqueous electrolyte lithium secondary battery comprising a positive electrode, a negative electrode capable of absorbing and desorbing lithium in a reversible manner and a non-aqueous electrolyte, wherein said positive electrode comprises a compound represented by the formula Li 1+x-y  M y  NiO 2+z , where M represents at least one element selected from the group consisting of Mg and Ca, and -0.1≦x≦0.1, 0.01≦y≦0.2, and -0.3≦z≦0.1. 
     
     
       6. A non-aqueous electrolyte lithium secondary battery comprising a positive electrode, a negative electrode capable of absorbing and desorbing lithium in a reversible manner and a non-aqueous electrolyte, wherein said positive electrode comprises a compound represented by the formula Li 1+x-y  (Mg a  Ca b  Co c  Al d ) y  NiO 2+z , where -0.1≦x≦0.1, 0.01≦y≦0.2, -0.3≦z≦0.2, and (a+b+c+d)=1, and any three or more of a, b, c and d are never 0 at the same time.